Stamped three-dimensional antenna

ABSTRACT

The embodiments described herein include a wireless-power-transmitting antenna formed from a stamped piece of metal. One such antenna includes: (i) a signal feed, defined by a single stamped piece of metal, that conducts a signal that controls wireless power transmission and (ii) resonators, each of which is defined by the single stamped piece of metal, that transmits power transmission waves in response to receiving the signal, where each resonator: (a) is planar with respect to a first plane and vertically aligned with each resonator, (b) is coupled to another resonator via curved sections of the stamped piece of metal that are in contact with the signal feed, each curved section extending along a second plane that is orthogonal to the first plane such that respective gaps are formed between each resonator, and (c) receives the signal via a respective curved section of the single stamped piece of metal.

This application is a continuation of U.S. patent application Ser. No. 14/930,580, filed on Nov. 2, 2015, entitled “Stamped Three-Dimensional Antenna,” which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD Background

Wireless charging of batteries of electronic devices has historically been performed by using inductive coupling. A charging base station receiver of an electronic device may have one or more coils in which a current may be applied to produce a magnetic field such that when another coil is place in close proximity, a transformer effect is created and power is transferred between the coils. However, such inductive coupling has a short range limit, such as a few inches or less. Examples of such wireless charging include electronic toothbrushes that are placed on a charging stand and inductive pads inclusive of one or more coils to enable electronic devices with coil(s) to be placed on the pads to be charged.

While inductive charging is helpful to eliminate users having to plug power cords into electronic devices for charging, the limited range at which electronic devices have to be positioned from charging stations is a significant shortcoming of the inductive charging technology. For example, if a user of a mobile device, such as a mobile telephone, is in a conference room without a charging pad or sufficient number of charging pads, then the user is unable to charge his or her phone without a traditional power cord.

Remote wireless charging has recently been developed. Remote wireless charging operates by generating a wireless signal inclusive of sufficient power to charge a battery of an electronic device. Such technology, however, has been limited due to technology advancements being a challenge, as transmitters, receivers, antennas, communications protocols, and intelligence of transmitters have all had to be developed (i) so that sufficient wireless power is able to be wirelessly directed to charge electronic devices and (ii) so that the remote wireless charging is safe and effective for people. One problem that exists for producing transmitter antennas is the cost of production due to parts and assembly of the parts to produce the transmitter inclusive of multiple, in some cases many, antennas that form an antenna array.

While certain advancements in remote wireless charging have occurred, acceptance of the new technology into homes and businesses (e.g., conference rooms) often requires design elements that extend beyond functionality. As an example, for remote wireless power charging that enables a transmitter to deliver high gain in small areas, three-dimensional (3D) transmitter antennas may be utilized. However, at frequencies used for the remote wireless charging of electronic devices, the 3D antennas have sufficiently large dimensions (e.g., depth) that consumers and businesses may resist such devices into their homes and offices as a result of undesirable aesthetics and dimensions that the 3D transmitter antennas extend from a wall on which the transmitters are mounted.

SUMMARY

To provide for transmit antennas of a transmitter of a remote wireless charging system that are cost effective and commercially acceptable to consumers and businesses, an antenna may be formed by stamping a piece of metal to form an “S”-shaped resonator element. The “S”-shaped antenna may be designed to have high gain performance through inductive-capacitive characteristics. In an embodiment, the antenna may have the resonator embedded in a dielectric substrate that enables the resonator element to be reduced in size as compared to the resonator element being exposed directly to the air.

One embodiment may include an antenna for transmitting wireless power signals. The antenna may include multiple horizontal resonator elements, where each horizontal resonator element is at least in part planar, vertically aligned, and in parallel with one another.

One embodiment of a method of manufacturing an antenna may include providing a piece of metal. The piece of metal may be stamped to form a series of horizontal resonator elements and vertical sections interconnecting the horizontal resonator elements along sequential opposing edges of the horizontal resonator elements to form an “S”-shaped antenna element. The “S”-shaped antenna element may be secured to a base member.

One embodiment of an antenna unit for transmitting a wireless power signal may include multiple antennas including multiple horizontal resonator elements. Each horizontal resonator element may be at least in part planar, vertically aligned, and in parallel with one another. The antennas may be positioned in at least one row to form an array of antennas.

Additional features and advantages of an embodiment will be set forth in the description which follows, and in part will be apparent from the description. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the exemplary embodiments in the written description and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constitute a part of this specification and illustrate an embodiment of the invention and together with the specification, explain the invention.

FIG. 1 is an illustration of an illustrative wireless power environment in which transmitters are configured to identify locations of one or more receivers inclusive of stamped antennas, and to communicate wireless power signals to those receiver(s) to form energy pocket(s) thereat, according to an exemplary embodiment.

FIGS. 2A-2C are illustrations of an illustrative stamped antenna, according to an exemplary embodiment.

FIG. 3 is an illustration of an illustrative alternative stamped antenna, according to an exemplary embodiment.

FIG. 4 is an illustration of an illustrative antenna gain pattern produced by the antenna of FIG. 3, according to an exemplary embodiment.

FIGS. 5A and 5B are illustrations of an illustrative alternative antenna configured with multiple horizontal resonator elements, according to an exemplary embodiment.

FIG. 6 is an illustration of an illustrative antenna unit inclusive of a plurality of stamped antennas with multiple horizontal resonator elements, according to an exemplary embodiment.

FIG. 7 is an illustration of an illustrative antenna unit inclusive of a plurality of stamped antennas with multiple horizontal resonator elements, according to an exemplary embodiment.

FIG. 8 is a flow diagram of an illustrative process for producing a 3D transmitter antenna inclusive of horizontal resonator elements, according to an exemplary embodiment.

FIG. 9 is a flow diagram of an illustrative process for producing a transmitter with a 3D transmitter antenna produced using the process of FIG. 8, according to an exemplary embodiment.

DETAILED DESCRIPTION

The present disclosure is herein described in detail with reference to embodiments illustrated in the drawings, which form a part here. Other embodiments may be used and/or other changes may be made without departing from the spirit or scope of the present disclosure. The illustrative embodiments described in the detailed description are not meant to be limiting of the subject matter presented here. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

Referring to FIG. 1, an illustration of an illustrative wireless power environment 100 in which transmitters 102 a, 102 b (collectively 102) are configured to identify a location of an electronic device 104 with a receiver 106 (or multiple receivers) inclusive of one or more receiver antennas (e.g., cross-polarized dipole antenna), and transmit wireless power signals or waves to the receiver 106 to cause RF signals to form constructive interference at the receiver 106 is shown. Although depicted with multiple transmitters 102, it should be understood that a single transmitter may be utilized. The transmitters 102 a, 102 b respectively include antenna arrays 108 a, 108 b (collectively 108) inclusive of respective antenna elements 109 a-109 m, 109 n-109 z (collectively 109). The transmitters 102 are used to transmit wireless power signals 110 a, 110 a (collectively 110) via the antenna elements 109. In one embodiment, the antenna arrays 108 a, 108 b have the same number of antenna elements. Alternatively, the antenna arrays 108 a, 108 b have a different number of antenna elements. Still yet, the antenna arrays 108 a, 108 b may have the same or different layouts or configurations of antenna elements. The antenna arrays 108 a, 108 b may have regularly spaced antenna elements or subsets of antenna elements with different spacings that are used for different types of transmissions of the wireless power signal.

Because the transmitters 102 are meant to be positioned in households and commercial settings, such as conference rooms, the transmitters 102 are to be sized in a manner with a small footprint and/or profile. Although the size of the footprint (e.g., width of overall antenna arrays) in some cases has to have a certain length for creating small energy pockets, the profiles (e.g., length of the antenna elements 109 along the z-axis that define the distance that the transmitters 102 extend from a wall) can be reduced to be more commercially viable for adoption by consumers and businesses.

The transmitters 102 may also include communication components 112 a, 112 b (collectively 112) that communicate with the electronic device 104. In one embodiment, the receiver 106 may be configured with a transmitter or other circuitry that enables communication with the communication components 112, thereby enabling the transmitters 102 to focus the wireless power signals 110 at the receiver 106 to form an energy pocket 114. The energy pocket 114 may be a localized region at which wireless power waves 110 form constructive interference (i.e., combined peaks of oscillation signals) that produces a combination of peak signals from each of the wireless power signals 110, as understood in the art.

Because the antenna arrays 108 may have orientations that cause the wireless power signals 110 to be communicated at different polarizations depending on an orientation of the electronic device with respect to the respective antenna arrays 108, the receiver 106 may include a cross-polarized dipole antenna, for example, so that orientation of the receiver 106 with respect to the antenna arrays 108 has minimal impact in an amount of power that is received from the wireless power signals 110.

To provide for cost effective antenna arrays 108, a structure for each of the antenna elements 109 may utilize a design that has a minimal number of parts and simplistic assembly process. In one embodiment, a stamped resonator element may be utilized in forming an antenna, and used to transmit a wireless power signal, as shown in FIG. 2. In an alternative embodiment, a series of horizontal resonator elements may be separated by dielectric slabs. In either configuration, the antenna element is defined by inductive-capacitive elements to enable a wireless power signal having a frequency over 900 MHz to be transmitted to charge or operate a wireless device.

With regard to FIGS. 2A-2C, an illustration of an illustrative stamped antenna resonator element 200 configured to transmit a wireless power signal is shown. The resonator element 200 is metallic, and configured to provide a certain inductive-capacitive (LC) response profile for transmitting a wireless power signal for use in remotely powering an electronic device and/or recharging a battery, as previously described. In an embodiment, the resonator element 200, when configured into an antenna (e.g., FIG. 3), operates at frequencies in a range from over 1 GHz to 100 GHz. More specifically, the center frequency may be about 1 GHz, 5.8 GHz, 24 GHz, 60 GHz, and 72 GHz with bandwidths suitable for operation (e.g., 200 MHz-5 GHz bandwidths), and the dimensions of the resonator element 200 may be configured to accommodate the frequencies of operation. For example, the design shown in FIG. 2 may be implemented at 5.8 GHz with 12-by-12 mm² patches that are separated by a 2 mm air gap.

The stamped resonator element 200 may be a stamped piece of metal. Alternative techniques for forming the resonator element 200 may be utilized, as understood in the art. The resonator element 200 includes a plurality of horizontal resonator elements 202 a-202 c (collectively 202) interconnected by vertical sections 204 a-204 c (collectively 204). As shown, the vertical sections 204 may not be perpendicular to the horizontal resonator elements 202, but may provide for a transition that separates the horizontal resonator elements 202 by a certain gap that provides for a predetermined inductive-capacitive response profile over a certain frequency range of operation. Feet 206 a-206 n (collectively 206) may be used to secure the resonator element 200 to a base. Each of the horizontal resonator elements may be at least in part planar, vertically aligned, and in parallel with one another. In being vertically aligned, at least a portion of each of the resonator elements 202 are disposed over one another. In one embodiment, the horizontal resonator elements 202 have the same size and shape and are aligned along a vertical axis.

A signal feed 208 is shown in FIGS. 2B and 2C to be positioned along one side of the stamped resonator element 200 to conduct RF signals thereto. Alternative signal feed configurations may be utilized to apply an RF signal onto the resonator element 200. The signal feed 208 may be formed by a stamping operation of a single piece of metal that forms the stamped resonator element 200 or may be formed by another piece of metal and connected to the resonator element 200. Alternatively, an induction technique may be utilized to apply the RF signal to the resonator element 200 for transmission of the wireless power signal. A base 202 c may operate as a ground plane, as understood in the art.

With regard to FIG. 3, an illustration of an illustrative alternative stamped antenna 300 is shown. The stamped antenna 300 includes a resonator member 302 inclusive of a plurality of horizontal resonator elements 304 a-304 n (collectively 304). Interconnecting each of the horizontal resonator elements 304 are vertical sections 306 a-306 n-1 (collectively 306). A base member 308 may be used to support the resonator member 302. In one embodiment, the base member 308 may operate as a ground plane. As shown, the horizontal resonator elements 304 and vertical sections 306 are normal to one another, and the vertical sections 306 interconnect the horizontal resonator elements 304 on alternating ends of the horizontal resonator elements 304 so as to form an “S”-shaped antenna member. As shown, the horizontal resonator elements 304 are square, but non-square shapes, such as rectangular, may be utilized in accordance with a desired antenna gain pattern. The bottom horizontal resonator elements 304 n may be configured with feet (not shown) that may be utilized to connect the resonator member 302 to the base member 308. Additional and/or alternative techniques, such as using an adhesive or fastening member (e.g., screw), for mounting the resonator member 302 to the base 308 may be utilized.

With regard to FIG. 4, an illustration of an illustrative antenna pattern 400 produced by the antenna 300 of FIG. 3 is shown. The antenna pattern 400 is shown to have a gain of over 9.5 dB along the z-axis with a gain of below −9.5 dB along the negative z-axis. As further provided herein, the antenna pattern 400 is different with different configurations of the antenna (i.e., different configurations of a base member and antenna element).

With regard to FIGS. 5A and 5B, illustrations of an illustrative alternative antenna 500 configured with multiple horizontal resonator elements 502 a-502 d (collectively 502) are shown. In one embodiment, and as shown, dielectric slabs 504 a-504 c (collectively 504) may be disposed between the horizontal resonator elements 502. The dielectric slabs 504 may be used to define a separation distance between the horizontal resonator elements 502, and provide for an inductive-capacitive response profile or value. A base 506 may be utilized to mount the horizontal resonator elements 502 of the antenna 500. A fastening member 508, such as a plastic or metallic screw, may be used to secure the horizontal resonator elements 502 and dielectric slabs 504 to the base 506. Alternative locations (e.g., along the edge) or fabrication techniques (e.g., adhesive bonding, multiple fastening members) may be utilized to secure the horizontal resonator elements 502 and dielectric slabs 504 together and to the base 506. The base 506 may be configured as a ground plane. A feed (not shown) may be used to conduct an RF signal to the horizontal resonator elements 502. In one embodiment, the feed may be applied along an edge of the horizontal resonator elements 502 or in a center region (e.g., at or near the screw) of the horizontal resonator elements 502.

With regard to FIG. 6, an illustration of an illustrative antenna unit 600 inclusive of a set of antennas 602 a-602 n (collectively 602) with resonator elements 604 a-604 n (collectively 604) that are the same or similarly configured as the antenna 300 provided in FIG. 3. It should be understood that the antennas 602 may be configured in the same or similar manner as antenna 500 of FIG. 5. In one embodiment, the antennas 602 are embedded within a substrate 606 a-606 n (collectively 606). The substrate 608 may be formed of ceramic, silicon, or other material that is a dielectric. The dielectric may have a permittivity greater than 5 F/m. The permittivity may be between approximately 9 F/m and approximately 10 F/m at a center frequency of the wireless signal. The wireless signal may have a frequency greater than 1 GHz. The stamped metal structures provide for communication of a wireless signal with multiple polarizations. There may be two or three different polarizations present at the same time. As a result of embedding the antennas 602 in the substrate 608, the dimensions of the resonator elements 604 and base members may be reduced, thereby enabling a smaller profile of an overall antenna unit.

A feed point (not shown) may be utilized to conduct a wireless power signal onto resonator elements 604 to transmit the wireless power signal to an electronic device, as described with regard to FIG. 1. In an embodiment, the antenna unit 600 operates at frequencies in a range from over 1 GHz to 100 GHz. More specifically, the center frequency may be about 1 GHz, 5.8 GHz, 24 GHz, 60 GHz, and 72 GHz with bandwidths suitable for operation (e.g., 200 MHz-5 GHz bandwidths), and the dimensions of the antennas may be configured to accommodate the frequencies of operation.

With further regard to FIG. 6, the antennas 602 may be disposed within antenna sub-units 608 a-608 n (collectively 608) defined by waveguide walls 610 a-610 n+1 (collectively 610) that may be formed of metal or other material that may be used to define the antenna subunits 608 and limit RF signals to interfere with adjacent antennas. Also defining the antenna sub-units 608 may be ground planes 612 a-612 n (collectively 612). Alternative embodiments may not include ground planes that define a portion of the antenna sub-units 608. Each of the antenna sub-units 608 a-608 n may include respective substrates 606 a-606 n. The substrates 606 may be the same substrate material. Alternatively, different substrate material may be used for the respective antenna sub-units 608, where the substrate in different antenna sub-units 608 may have different properties (e.g., different permittivity). The substrates 606 may be ceramic.

In manufacturing the antenna sub-units 608, the waveguide walls 610 and ground planes 612 (or non-ground plane bottom structural component) may be assembled to define the antenna sub-units 608. The antennas 602 may be positioned within the assembled waveguide walls 610 and ground planes 612 that define the antenna sub-units 608, and then the substrates 606 may be poured while in a flowable or injectable state to embed the antennas 602 and allowed or activated to transition to a solid state. Electrical conductors (not shown) may be connected to the antennas 602 prior to adding the substrates 606. Although shown as being a linear array, it should be understood that the antenna unit 600 may be configured as a 2D matrix of antennas 602, such as the antenna arrays 108 shown in FIG. 1.

With regard to FIG. 7, an illustration of an illustrative antenna unit 700 inclusive of a plurality of antennas 702 a-702 n (collectively 702) with multiple horizontal resonator elements is shown. In one embodiment, the antenna unit 700 may include a ground plane 704 that in part contributes to shaping an antenna pattern from the antenna unit 700. The antennas 702 collectively provide for an array of antennas such that an overall antenna pattern is formed, and phasing of wireless power signals communicated from the array of antennas may enable an antenna pattern to be directed as understood with phased array antennas. The antenna unit 700 does not include waveguide walls, such as the waveguides walls 610 of FIG. 6, that help to isolate the antennas 702 from one another to reduce cross-talk. However, the substrate 706 helps attenuate near field signals to reduce cross-talk between adjacent antennas 702. The substrate 706 that embeds multiple antenna elements may be considered a casting. The substrate 706 may be a dielectric, such as a ceramic material or silicon material.

With regard to FIG. 8, a flow diagram of an illustrative process 800 for producing a 3D transmitter antenna inclusive of horizontal resonator elements is shown. The process 800 may start at step 802, where a piece of metal may be provided. At step 804, the piece of metal may be stamped to form a series of horizontal resonator elements and vertical sections interconnecting the horizontal resonator elements along sequential opposing edges of the horizontal resonator elements to form an “S”-shaped antenna element or resonator member. The “S”-shaped antenna element may have either perpendicular or curved connections between the horizontal resonator elements and vertical sections. At step 806, the “S”-shaped resonator member may be secured to a base member. In securing the resonator member to the base member, feet that are formed during the stamping process may be used to secure the resonator member. Alternatively and/or additionally, the antenna element may be directly or indirectly secured to the base member using an adhesive and/or fastening members. In one embodiment, the base member may be a ground plane. A dielectric slab may be disposed between the antenna element and base member.

With regard to FIG. 9, a flow diagram of an illustrative process for producing a transmitter antenna array with one or more 3D transmit antennas produced using the process of FIG. 8 is shown. The process 900 may start at step 902, where a plurality of antennas including a plurality of horizontal resonator elements, each having a length and a width, are vertically aligned and in parallel with one another. The vertical alignment may have each of the horizontal resonator elements being centrally aligned. The horizontal resonator elements may be identical in dimension. Alternatively, the dimensions of the horizontal resonator elements may be different. The forming may be performed by stamping a piece of metal. Alternatively, the forming may include stacking a plurality of horizontal resonator elements with dielectric slabs disposed between the horizontal resonator elements. At step 904, the antennas may be positioned in at least one row to form an array of antennas.

One embodiment of a device for wirelessly charging a battery may include a transmitter unit including a transmitter and an antenna unit in communication with the transmitter. The antenna unit may include multiple 3D antenna elements configured to communicate a wireless signal for use in charging a battery. The battery may be in a mobile device, such as a mobile telephone. The 3D antenna elements may be a stamped antenna 300 as shown in FIG. 3 or antenna 500 as shown in FIG. 5.

The antenna unit may be configured as a linear array. The linear array may be longer than 2 feet. The linear array may be formed by multiple linear arrays including a space disposed between the multiple linear arrays. The antenna unit may be configured as a matrix. The 3D antenna elements may be regularly spaced. Alternatively, the antenna elements may be variably spaced. The 3D antenna elements may be grouped into sub-arrays, and the sub-arrays may be selectable for communicating wireless signals by the selected sub-arrays. The 3D antenna elements may be individually selectable or selected in rows or groups. A processing unit may be configured to cause a transmitter to generate a signal, and communicate the wireless power signal via the 3D antenna element(s).

The foregoing method descriptions and the process flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. The steps in the foregoing embodiments may be performed in any order. Words such as “then,” “next,” etc. are not intended to limit the order of the steps; these words are simply used to guide the reader through the description of the methods. Although process flow diagrams may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination may correspond to a return of the function to the calling function or the main function.

The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein. 

What is claimed is:
 1. A wireless-power-transmitting antenna comprising: a signal feed configured to conduct a signal that causes the antenna to transmit electromagnetic (EM) power transmission waves; and a unitary resonator formed from a single piece of metal, the unitary resonator including a plurality of planar segments interconnected by respective sections, wherein the plurality of planar segments includes: (i) a first planar segment positioned on a first horizontal plane; (ii) a second planar segment, adjacent to the first planar segment, positioned on a second horizontal plane vertically offset from the first horizontal plane by a first respective section interconnecting the first and second planar segments; and (iii) a third planar segment, adjacent to the second planar segment, positioned on a third horizontal plane vertically offset from the second horizontal plane by a second respective section interconnecting the second and third planar segments, and further wherein the signal feed directly contacts at least two planar segments of the plurality of planar segments.
 2. The antenna of claim 1, wherein: the unitary resonator is configured to transmit the EM power transmission waves in response to receiving the signal from the signal feed; and the EM power transmission waves transfer energy that is used by a wireless power receiver to power or charge an electronic device coupled with the wireless power receiver.
 3. The antenna of claim 1, wherein: the second planar segment includes opposing first and second edges; the first respective section interconnecting the first and second planar segments extends from the first edge of the second planar segment in a first direction; and the second respective section interconnecting the second and third planar segments extends from the second edge of the second planar segment in a second direction.
 4. The antenna of claim 1, wherein the first and second respective sections are curved.
 5. The antenna of claim 1, wherein the first and second respective sections are perpendicular to the first, second, and third planar segments.
 6. The antenna of claim 1, wherein the first, second, and third planar segments are vertically aligned along an axis.
 7. The antenna of claim 6, wherein: the second planar segment is vertically offset from the first planar segment by a first distance; and the third planar segment is vertically offset from the second planar segment by a second distance.
 8. The antenna of claim 1, wherein: the first planar segment includes a plurality of feet; and the antenna further comprises a base member coupled to and offset from the first planar segment by the plurality of feet.
 9. The antenna of claim 8, wherein the base member is a ground plane and the ground plane grounds the antenna.
 10. The antenna of claim 1, wherein each of the plurality of planar segments is identical in size and shape.
 11. The antenna of claim 10, wherein the first distance and the second distance are the same.
 12. The antenna of claim 1, wherein the unitary resonator has an S-shape.
 13. The antenna of claim 1, wherein: a space between the first and second planar segments is filled with a first dielectric material; and a space between the second and third planar segments is filled with a second dielectric material.
 14. The antenna of claim 1, wherein the EM power transmission waves are transmitted at a frequency that is based on one or more characteristics of the plurality of planar segments.
 15. The antenna of claim 14, wherein one of the one or more characteristics is an inductive-capacitive response.
 16. The antenna of claim 1, wherein: the first planar segment, the second planar segment, and the third planar segment are 12-by-12 mm patches; the second planar segment is vertically offset from the first planar segment by 2 mm; and the third planar segment is vertically offset from the second planar segment by 2 mm.
 17. A wireless-power-transmitting device comprising: a plurality of wireless-power-transmitting antennas, wherein each wireless-power-transmitting antenna comprises: a signal feed configured to conduct a signal that causes the antenna to electromagnetic (EM) transmit power transmission waves; and a unitary resonator formed from a single piece of metal, the unitary resonator including a plurality of planar segments interconnected by respective sections, wherein the plurality of planar segments includes: (i) a first planar segment positioned on a first horizontal plane; (ii) a second planar segment, adjacent to the first planar segment, positioned on a second horizontal plane offset and aligned from the first horizontal plane by a first section interconnecting the first and second planar segments; and (iii) a third planar segment, adjacent to the second planar segment, positioned on a third horizontal plane offset and aligned from the second horizontal plane by a second section interconnecting the second and third planar segments, and further wherein the signal feed directly contacts at least two planar segments of the plurality of planar segments.
 18. The wireless-power-transmitting device of claim 17, wherein the plurality of planar segments is: configured to transmit the EM power transmission waves in response to receiving the signal from the signal feed; and the EM power transmission waves transfer energy that is used by a wireless power receiver to power or charge an electronic device.
 19. The wireless-power-transmitting device of claim 17, wherein: the second planar segment includes opposing first and second edges; the first respective section interconnecting the first and second planar segments extends from the first edge of the second planar segment in a first direction; and the second respective section interconnecting the second and third planar segments extends from the second edge of the second planar segment in a second direction.
 20. The wireless-power-transmitting device of claim 17, wherein the first and second respective sections are curved.
 21. The wireless-power-transmitting device of claim 17, wherein: the first planar segment, the second planar segment, and the third planar segment are 12-by-12 mm patches; the second planar segment is vertically offset from the first planar segment by 2 mm; and the third planar segment is vertically offset from the second planar segment by 2 mm. 